This seems taken out of context. I don't think he was making a blanket statement, he was asking if people are willing to pay for this particular service, is it unethical? Ie, is it reasonable to say that if people are willing to pay for restaurant reservations, specifically, does that say anything about the ethics of it. Not to say that it is a good point, but I don't think it's some moral statement that paying for something makes it de facto ethical in general.
"If somebody is willing to pay for it, is it really unethical?"
There we go - if there's a paying market for something, it's totally ethical. Off I go to found assasins.io - murder for hire disrupted.